1. Field of the Invention
The present invention relates to a production planning system.
2. Description of the Background Art
In a case where a wide variety of low volume products are manufactured, plural production lines are run in parallel. Each of the production lines has plural units of equipment to be required for manufacturing products and assignment is made of necessary equipment used for manufacturing on-order products. Since a product is generally manufactured through plural steps, each production line has plural units of equipment installed necessary for manufacturing products in each step and assignment is made of equipment required for manufacturing the products in each step.
Furthermore, differences arise, between production lines, in aspects of equipment used in a line, a process time, a yield, a production capacity and so on and, according to an on-order product, in necessary number of steps for its manufacturing.
In production planning for on-order products using such plural production lines, consideration is given to parameters such as an operational status of each production line (an availability factor), a process time of each production line and a process time of each step.
However, when a trouble occurs in a step of a production line, a great influence of the trouble is exercised on steps subsequent to the troubled step.
Furthermore, when a processing capacity of a production line becomes insufficient or a quality of products in a production line is degraded, a change of production line is required.
Still furthermore, when a change in size of semiconductor wafers fed into a line occurs, a change in equipment used in the line is required.
In such cases, while a production plan is rearranged, there arises a problem of difficulty in arranging an optimal production plan because of complex entanglement associated with plural production lines, a plural steps, plural units of equipment and others.
It is accordingly an object of the present invention to provide a production planning system capable of arranging a production plan in a production line for a variety of products with ease.
According to the present invention, a production planning system is a system selecting a production line suited for manufacturing on-order products from plural production lines each used for manufacturing a variety of products to arrange a production plan in the selected production line including equipment priority calculation section calculating priorities of kinds of equipment that can be used for manufacturing the on-order products based on equipment information showing a kind of equipment applicable in each of the plural production lines; and product information, including information on a kind of equipment suited for manufacturing the on-order products, and necessary for manufacturing the on-order products; a line priority calculation section calculating priorities of production lines that can be used for manufacturing the on-order products based on quality information on each of a variety of products in each of the plural production lines and the product information; and a production planning section determining a production line suited for manufacturing the on-order products based on the priorities of kinds of equipment calculated in the equipment priority calculation section, the priorities of production lines calculated in the line priority calculation section, the number of the on-order products and statuses of the plural production lines to assign equipment necessary for manufacturing the on-order products and capable of being used to the determined production line and to thereby, arrange a production plan for the on-order products.
Therefore, according to the present invention, since priorities of kinds of equipment in each of production lines and priorities of the production lines are calculated based on information on equipment used, a yield and necessary information for manufacturing on-order products in each of the production lines and a production plan is arranged using a delivery time of the on-order products and a current status of each of the production lines in addition to the priorities of the kinds of equipment and the priorities of the production lines calculated, a production plan for the on-order products can be arranged with ease even if a trouble occurs in the production line and/or a size of semiconductor wafers fed in the production line is changed.